I suspect they must be including TV series DVDs to get that number. Any given Target or Best Buy will have two dozen movies available at $5, but that's only a tiny fraction of their stock, and generally only the really unpopular stuff. I might believe $7-8 average for single disc movies. But start factoring in 6-disc TV seasons for $20 and you might get there.

6 for $20? Try 5-6 for $10 around christmas time. For some reason, I actually bought the first 5 seasons of House MD for that from Target one year. Fry's had good deals on seasons of X-Files too, so I got the first 5 of the 10 seasons of that too. I still haven't gotten to watching X-Files in order yet. I'm currently working on Babylon 5, so I'm getting through my collection of stuff slowly but surely.